Helder Rojas

Helder Rojas


Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2026 in Scientia Agricola
Verified
Journal Article
Open access
RGRita Rocio Guzman-Lopez
Rita Rocio Guzman-Lopez
Luis Huamanchumo de la CubaLuis Huamanchumo de la Cuba
Luis Huamanchumo de la Cuba
KMKevin Anthony Fernandez Molina
Kevin Anthony Fernandez Molina
OCOscar Diego Fernando Cutipa-Luque
Oscar Diego Fernando Cutipa-Luque
YYYhon Tiahuallpa Yucra
Yhon Tiahuallpa Yucra
HRHelder Rojas
Helder Rojas
This study presents a novel approach that combines agricultural census data with remotely sensed time series to develop accurate predictive models for paddy rice yield across the different regions of Peru. By leveraging sparse regression and Elastic-Net regularization techniques, the study uncovers causal relationships between key remotely sensed variables such as Normalized Difference Vegetation Index (NDVI), precipitation (PREC), temperature (TEMP), and agricultural yield. To further enhance prediction accuracy, first- and second-order dynamic transformations (velocity and acceleration) of these variables were applied to capture non-linear patterns and lagged effects on yield. The findings demonstrate improved predictive performance when integrating regularization techniques with climatic and geospatial variables, allowing for more accurate forecasts of yield variability. The results confirm the presence of causal relationships in the Granger sense, underscoring the value of this methodology to strategic agricultural management. This contributes to more efficient and sustainable production in paddy rice cultivation.

1 December 2025 in Physica Scripta
Verified
Journal Article
Closed access
CECarlos Escudero
Carlos Escudero
HRHelder Rojas
Helder Rojas
Interpreting the noise in a stochastic differential equation, in particular the Itô versus Strato-novich dilemma, is a problem that has generated a lot of debate in the physical literature. In the last decades, a third interpretation of noise, given by the so-called Hänggi–Klimontovich integral, has been proposed as better adapted to describe certain physical systems, particularly in statistical mechanics. Herein, we introduce this integral in a precise mathematical manner and analyze its properties, signaling those that have made it appealing within the realm of physics. Subsequently, we employ this integral to model some statistical mechanical systems, such as the random dispersal of Langevin particles and the relativistic Brownian motion. We show that, for these classical examples, the Hänggi–Klimontovich integral is worse adapted than the Itô integral and even the Stratonovich one.

4 August 2025 in Physical Review Research
Verified
Journal Article
Open access
CRConnor Roberts
Connor Roberts
ZZZiluo Zhang
Ziluo Zhang
HRHelder Rojas
Helder Rojas
SBStefano Bo
Stefano Bo
CECarlos Escudero
Carlos Escudero
GPGunnar Pruessner
Gunnar Pruessner
We introduce “stochastic cloaking,” where a region of space is concealed from an ensemble of diffusing particles whose individual trajectories are governed by a stochastic (Langevin) equation. Our simulations reveal how different interpretations of the Langevin equation affect the cloaking performance of an annular single-layer invisibility cloak of smoothly varying diffusivity in two dimensions. Near-perfect cloaking is achieved under the Itô convention, indicated by the cloak preventing particles from accessing an inner core without disturbing the particle density outside the cloak. The cloak's performance can be further improved by regularizing its singular behavior. We believe our demonstration of stochastic cloaking is a significant milestone, comparable to earlier developments that extended cloaking from optics and acoustics to thermodynamics.

19 May 2020 in Applied Stochastic Models in Business and Industry
Verified
Journal Article
Closed access
PDF file
HRHelder Rojas
Helder Rojas
DDDavid Dias
David Dias

17 November 2019 in Applied Stochastic Models in Business and Industry
Verified
Journal Article
Closed access
PDF file
HRHelder Rojas
Helder Rojas
DDDavid Dias
David Dias

23 October 2025 in arXiv
Verified
Preprint
Open access
PDF file
CECarlos Escudero
Carlos Escudero
HRHelder Rojas
Helder Rojas
Diffusion theory establishes a fundamental connection between stochastic differential equations and partial differential equations. The solution of a partial differential equation known as the Fokker-Planck equation describes the probability density of the stochastic process that solves a corresponding stochastic differential equation. The kinetic interpretation of noise refers to a prospective notion of stochastic integration that would connect a stochastic differential equation with a Fokker-Planck equation consistent with the Fick law of diffusion, without introducing correction terms in the drift. This work is devoted to identifying the precise conditions under which such a correspondence can occur. One of these conditions is a structural constraint on the diffusion tensor, which severely restricts its possible form and thereby renders the kinetic interpretation of noise a non-generic situation. This point is illustrated through a series of examples. Furthermore, the analysis raises additional questions, including the possibility of defining a stochastic integral inspired by numerical algorithms, the behavior of stochastic transport equations in heterogeneous media, and the development of alternative models for anomalous diffusion. All these topics are addressed using stochastic analytical tools similar to those employed to study the main problem: the existence of the kinetic interpretation of noise.